1. Field of the Invention
The present invention relates to an image forming apparatus configured to form an image on a recording medium by electrophotography, electrostatic recording, magnetic recording, or the like.
2. Description of the Related Art
An electrophotographic image forming apparatus is now described as an example. Examples of the electrophotographic image forming apparatus include an electrophotographic copier, an electrophotographic printer (LED printer, laser beam printer, and the like), an electrophotographic facsimile device, and an electrophotographic image display device (electronic blackboard, electronic whiteboard, display device, and the like). It may be necessary to check whether or not the image forming apparatus is ready for image formation before an image is formed thereby. Some exemplary image forming apparatus that are configured so that a member such as an image bearing member (photosensitive drum) or a developer carrying member is removably mountable to an apparatus main body of the image forming apparatus in the form of a cartridge perform control of detecting whether or not the cartridge is properly mounted to the apparatus main body.
Exemplary image forming apparatus that are configured to determine whether the cartridge is not mounted or properly mounted to the apparatus main body are disclosed in Japanese Patent Application Laid-Open No. H11-015337 and Japanese Patent No. 3416664.
In the image forming apparatus disclosed in Japanese Patent Application Laid-Open No. H11-015337, a voltage is applied to a photosensitive drum included in a process cartridge from a transfer device which is in contact with the photosensitive drum, and a current flowing through the photosensitive drum is detected by a detection circuit of the apparatus main body. In this way, the image forming apparatus determines the mount state of the process cartridge.
In the image forming apparatus disclosed in Japanese Patent No. 3416664, an AC detection voltage is applied to a developer carrying member included in a process cartridge which is removably mountable to the apparatus main body, and an induced current flowing through an antenna member included in the process cartridge is detected by a detection circuit of the apparatus main body. In this way, the image forming apparatus determines the mount state of the process cartridge.
Another conventional technology is the structure in which a developing device is movable inside the image forming apparatus (Japanese Patent No. 4402137). In this structure, the state in which a developer carrying member provided in the developing device is brought into contact with an image bearing member and the state in which the developer carrying member is separated from the image bearing member are switched for image formation and non-image formation. It is therefore desired to confirm that the developer carrying member may become properly in contact with the image bearing member or separated from the image bearing member before image formation is performed by the image forming apparatus.